By Lee Chi-dong SINGAPORE, June 5 (Yonhap) -- South Korean President Lee Myung-bak assured Singaporean business leaders Saturday that there will never be a full-scale war on the Korean Peninsula despite rising tensions between the two Koreas in the wake of the March sinking of a South Korean warship.

"The South-North Korean issue should be resolved by all means but it is clearly not an easy task," Lee said in a meeting with a dozen Singaporean business leaders, including Tony Chew, chairman of Singapore Business Federation, according to presidential spokesman Park Sun-kyoo.

"But there is no chance of a full-scale war at all," the president was quoted as saying, adding he will also try to prevent the recurrence of a skirmish between the sides.

Lee was apparently seeking to dispel worries over the security condition on the peninsula where tensions have escalated since the South accused the North of torpedoing one of its warships, the Cheonan, and sinking it, killing 46 sailors.

South Korea has pressed ahead with punitive steps in spite of the North's threats of war.

Lee also asked Singaporean firms to expand investment in South Korea, saying it is a good opportunity to do so as South Korea's economy is fast recovering, the spokesman said.

In a 30-minute meeting with U.S. Secretary of State Robert Gates, who is in Singapore to attend the Shangri-La Dialogue, an annual regional security forum, the president appreciated Washington's support for Seoul's handling of the Cheonan sinking. South Korea formally requested Friday the U.N. Security Council discuss penalties against the North.

"Gates relayed President Barack Obama's position to continue active support for the South Korean government in connection with the issue," the spokesman said at a press briefing.

The secretary told Lee that the U.S. will let South Korea take the initiative in fixing the schedule for a planned joint anti-submarine drill between the allies and dealing with the Cheonan incident at the U.N. Security Council, Park said.

The South Korean and U.S. navies originally planned to hold the exercise, which would involve the nuclear-powered aircraft carrier USS George Washington, next week, but it has been postponed in consideration of U.N. diplomacy.

Addressing the security conference, Gates said it would set a "very bad precedent" to let North Korea go unpunished over its latest naval attack.

He stressed the need for making the North pay a price in a bid to head off the possibility of additional provocations.

The South Korean president and Gates, however, did not touch on the sensitive issue of the timing of South Korea regaining wartime operational control (OPCON) of its troops, officials said. Conservatives in South Korea have called for a delay in the OPCON transfer, slated for 2012, saying the sinking proves the transition would be premature.

Meanwhile, the South Korean president had a summit with Prime Minister Lee Hsien Loong later Saturday on ways to foster bilateral partnership.

It was not immediately confirmed whether Lee had asked Singapore to positively consider purchasing South Korea's T-50 Golden Eagle supersonic trainer jets during the summit.

South Korea is reportedly in a two-way competition with Italy for Singapore's project to procure advanced trainer jets. The winner is expected to be decided in a few months, sources said.

On the occasion of Lee's trip here, the two sides also signed two memorandums of understanding on expanding joint assistance to developing countries and boosting ties on the safety of pharmaceutical products, cosmetics and medical devices.

Lee was about to wrap up his two-day stay here during which he delivered a keynote speech at the Shangri-La Dialogue to stress the importance of international unity to punish the North for the Cheonan case. He is scheduled to return to Seoul on Saturday night.